Grinnell Arena (Building #136) and the Abattoir Slaughter House (Building #137) are connected buildings. Grinnell Area was constructed in 1911 and the Abattoir Slaughter House was built onto its west side in 1929.

Grinnell Arena is 2½-story Arts & Crafts brick structure with a hip roof and front gables on its north and south elevations. The building is one bay wide and 12 bays deep, with a granite foundation, an asphalt shingle roof and wood replacement windows. The building’s Arts & Crafts characteristics include the use of a hip roof with a broad overhang and the use of a combination of traditional building materials including stone, brick and stucco in a single architectural composition.

Grinnell Arena’s main entry is in its one-bay wide north elevation, within the central section of the elevation that also contains the front gable. The doorway is sheltered by a modern shed roof porch hood. The double-leaf door, which is also modern, has 2/2 panes in the upper half of each leaf. Aside from the door opening, the rest of the north elevation’s first story is blank brick wall. The second story contains a large semicircular window with a central mullion, which is set within a brick arch in the gable peak, directly above the porch hood. This window is 3/6 at the highest and widest points of the semicircle. At either side of the semicircular window is a slightly recessed set of paired 3/3 rectangular windows, which are located immediately below the eaves and are framed by a rectangular opening in the brick wall that is wider than the paired windows. The wall space between the outer ends of the paired windows and the brick frame is coated with stucco. The building’s south elevation matches its north elevation.

Early 20th century photographs on file at Special Collections and Archives, W.E.B Du Bois Library, University of Massachusetts Amherst show that the doorway originally contained a double-leaf barn door with 3/2 panes in the upper third of each leaf and X-shaped cross pieces in the lower two-thirds of each leaf. These historic photographs also show that the original semicircular window was similar to the existing window but had a thicker central mullion. In addition, the historic photos show that the building originally had stucco panels at the ends of the paired windows on the north elevation, and the brick framing did not originally contain three 3/3 windows.

Grinnell Arena’s 12-bay wide east elevation has two brick piers, which visually divide the exterior wall into three sections. The central section is twice as wide as each of the end sections. The east elevation’s first story contains 11 window openings and one door, which are clustered into four groups of three closely spaced openings. Seven of the 11 windows frames have been blocked and one has been fitted with louvers. One 2/3 casement window remains at the southern end, and the pair of windows flanking the blocked doorframe at the northern end retain their 2/3 casement windows. Early 20th century photographs show that all 11 original windows were 2/3 casements and the door had 3/2 fixed panes in its upper third.

The east elevation’s second story has recessed stucco panels between the brick piers. Historic photographs show that the second story originally contained four sets of triple windows that were flanked by stucco panels. Each triple window consisted of a central 4/2 window with a 3/2 window on either side. The east elevation’s attic story has two hip roof dormers, which are blocked with bead board. Historic photographs show that each dormer originally contained a triple window that was identical to the second story’s triple windows. The west elevation is similar to the east elevation, except that the upper story retains a few of its windows. Originally, the west elevation contained larger windows and more doors on its lower level, which is completely above grade level on this side of the building. The Abattoir Slaughter House addition to the west elevation contains sets of triple 2/2 windows and has a hip roof. The brick and stone masonry of the Abattoir matches that of Grinnell Arena, and the Abattoir’s Arts & Crafts-inspired exterior is in keeping with that of Grinnell, albeit somewhat more simplified in terms of window and door styles.

Grinnell Arena was built in 1911 as an animal husbandry building livestock judging arena. The Abattoir Slaughter House was added to the west side of Grinnell Arena in 1929. Together, these two buildings represent a continuation of the Trustee’s commitment to upgrade the College’s physical plant with state-of-the-art agricultural and teaching facilities. Grinnell Arena and Abattoir Slaughter House were built as part of the Brooks Barn Complex, a series of buildings that were intended to serve as the center of livestock husbandry for the College. Other buildings in this group include the extant 1894 Horse Barn (Building #166) and Blaisdell House (Building #38), as well as a number of no longer extant barns and ancillary structures. These demolished buildings included the farm hands dormitory/milker’s bungalow, the east cow stable and dairy complex, and a silage storage building. The Brooks Barn Complex continued to function as a center of livestock husbandry for the University into the 1960s when such agricultural operations were relocated to new facilities in East Deerfield, Massachusetts. The arena and abattoir now house facilities for the university's marching band.

Grinnell Arena (1911) and the Abattoir Slaughter House (1929) were constructed along the south side of a road that ran from North College (no longer extant) to the west between the 1894 Horse Barn and Grinnell Arena. Historic plans show that the road widened to a forecourt between the Grinnell Arena and the 1894 Horse Barn. A 1943 plan shows trees lining the south side of the road (no longer extant). The western end of the complex is connected to the George N. Parks Minuteman Marching Band Building, which was completed in 2011. A bituminous concrete parking lot was added to the south of Abattoir Slaughter House following the building’s construction and has significantly changed the landscape context of the building.